T-Mobile USA Inc. may be required to pay an auto racing team as much as $14 million after the U.S. Court of Appeals for the Third Circuit remanded the case back to the U.S. District Court for the District of Delaware to calculate additional damages.

The District of Delaware ordered the telecom giant to pay $7 million to the racing team after it pulled out of a sponsorship contract, but said the contract’s full $14 million value would amount to “an unfair windfall” because the team did nothing to mitigate its damages. In a precedential opinion, the Third Circuit held the party breaching a contract has the burden of proving whether the other party took reasonable steps to mitigate its losses.